A topic from AEG's L5R CCG Rules forum, copied for Oracle of the Void from a copy of the forum saved in October 2015, so pages it didn't save are missing. Players' names are left out; the rules officials are named. Rulings are as they stood on these dates; later rulings, the rulebooks and the Rules Archive may differ.
A player, 4 March 2012
If somebody announces the equip action, and after picking their card and having it 'entering play' they then check restrictions, they then pay for gold for its costs. Lets say they announce they are using library of rebirth's reaction to pay for a spell during battle because all available holdings are bowed. However somebody then players footsteps of madness to negate the gold production so now they cannot pay for the spell with any other means. What happens to the spell?
My understanding is that the card has already left the players hand and entered a special 'entering play' location that is visable to all players (unlike their hand) so that is where it is currently stuck when they cannot pay for it.
I feel like the rules usually favor the user original user and would let them return the card to their hand if they can't pay for it any other way. But if it returns to the hand it could trigger entering hand effects (like Isawa Kimi's reaction) which seems strange.
Alex Jones (rules official), 5 March 2012
If somebody announces the equip action, and after picking their card and having it 'entering play' they then check restrictions, they then pay for gold for its costs. Lets say they announce they are using library of rebirth's reaction to pay for a spell during battle because all available holdings are bowed. However somebody then players footsteps of madness to negate the gold production so now they cannot pay for the spell with any other means. What happens to the spell?
My understanding is that the card has already left the players hand and entered a special 'entering play' location that is visable to all players (unlike their hand) so that is where it is currently stuck when they cannot pay for it.
I feel like the rules usually favor the user original user and would let them return the card to their hand if they can't pay for it any other way. But if it returns to the hand it could trigger entering hand effects (like Isawa Kimi's reaction) which seems strange.
Card types, Playing attachments: D. The player pays the attachment's Gold cost and any other costs of bringing it into play (see Costs). If costs are interfered with and not fully paid, the attachment card returns to where it came from and the sequence ends; if the attachment came directly from a search of a deck, it is shuffled back into the deck.
Note that returning a card to hand in this way will not trigger Isawa Kimi's Reaction, since it's a rulebook effect, not an effect of the Equip action.